Africa's grandest canyon

By sheer numbers, this Namibian ravine doesn't quite stack up against the more familiar Grand Canyon: At 100 miles long and 1,800 feet deep, Fish River Canyon is less than half the Arizona landmark's size. But as a master sculptor of scenery, the shallow and seasonal Fish River gives the mighty Colorado a run for its money. Along the Fish's banks, a 50-mile trail affords hikers incredible views for days (most tackle it in about five). And as further reward, the hot spring resort of ǀAi-ǀAis awaits at the trail's terminus.